If you've tried to find P/N 457 193 R1, you too, have discovered that it is NLA. Used parts houses don't have them often, and I suppose Ebay might have one once in a while. If you do find one, I'm sure it is priced like it is made of unobtanium.

Being undaunted, and an independent little b*****d, I wandered through Tractor Supply in the quest for the Holy Grail. What I did find was a PTO adaptor (P/N 271067 $29.99) and a 4 1/2" (P/N 4300070 $7.99) pulley. I already had a Hub City 10-to-6 spline adaptor (P/N 0332-00355).

This is what I did. After getting the measurements, I chucked the PTO adaptor in my lathe and turned it until its diameter was just a fraction less than the hole in the pulley, a slip-fit. I then arc welded the pulley to the modified PTO adaptor, and slipped in the 10-6 adaptor. Two hours.